Ingredient info:Hot chili paste is sold at Asian markets and many supermarkets.

Preparation

Using small kitchen scissors, cut shrimp
shells along the curved backs. Remove vein,
keeping shell intact. (Skip this step if using
peeled deveined shrimp.) Toss shrimp and
next 9 ingredients in a large bowl.

Place four 16x12" sheets of heavy-duty
foil on a work surface. Divide shrimp mixture
among sheets. Fold all foil edges toward the
center to accommodate the liquid; do not
crimp. Add 2 tablespoons butter and 1/4 cup water
to each. Crimp tightly to seal. Preheat oven
to 325°F. Arrange packets in a single layer on
a rimmed baking sheet. Alternatively, build a
medium fire in a charcoal grill, or preheat
a gas grill to medium-high. Bake or grill until
shrimp are just opaque in center (carefully
open 1 packet to check; steam will escape),
about 30 minutes. Carefully cut open
packets.